Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Life-cycle assessment of an industrial direct air capture process based on temperature–vacuum swing adsorption


Current climate targets require negative carbon dioxide (CO2) emissions. Direct air capture is a promising negative emission technology, but energy and material demands lead to trade-offs with indirect emissions and other environmental impacts. Here, we show by life-cycle assessment that the commercial direct air capture plants in Hinwil and Hellisheiði operated by Climeworks can already achieve negative emissions today, with carbon capture efficiencies of 85.4% and 93.1%. The climate benefits of direct air capture, however, depend strongly on the energy source. When using low-carbon energy, as in Hellisheiði, adsorbent choice and plant construction become more important, inducing up to 45 and 15 gCO2e per kilogram CO2 captured, respectively. Large-scale deployment of direct air capture for 1% of the global annual CO2 emissions would not be limited by material and energy availability. However, the current small-scale production of amines for the adsorbent would need to be scaled up by more than an order of magnitude. Other environmental impacts would increase by less than 0.057% when using wind power and by up to 0.30% for the global electricity mix forecasted for 2050. Energy source and efficiency are essential for direct air capture to enable both negative emissions and low-carbon fuels.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Flowchart and adsorption–desorption phase of the DAC process by Climeworks.
Fig. 2: Carbon footprint of captured CO2 depending on the carbon footprint of electricity from cradle-to-gate.
Fig. 3: Carbon footprint of the adsorbents considered, over their entire life cycle.
Fig. 4: Carbon footprint breakdown analysis for the construction of the DAC plant.
Fig. 5: Carbon footprint of captured CO2 depending on the carbon footprint of the electricity supply from cradle-to-grave.
Fig. 6: Material and energy requirements capturing 1% of the global annual CO2 emissions.
Fig. 7: Normalized environmental impacts for capturing 1% of the annual global CO2 emissions (0.368 GtCO2 yr–1).

Data availability

Data on the LCI, the studied scenarios and the resulting environmental impacts are available within this paper and the Supplementary Information. More details on the datasets generated and/or analysed during the current study are not publicly available since they contain commercially relevant information from Climeworks, but are available from the corresponding author on reasonable request and with permission of Climeworks.


  1. 1.

    Tollefson, J. The hard truths of climate change — by the numbers. A set of troubling charts shows how little progress nations have made toward limiting greenhouse-gas emissions. Nature (2019).

  2. 2.

    Le Quéré, C. et al. Temporary reduction in daily global CO2 emissions during the COVID-19 forced confinement. Nat. Clim. Change, 10 647–653 (2020).

  3. 3.

    Report of the Conference of the Parties on its Twenty-First Session Decision 1/CP.21 (United Nations Framework Convention on Climate Change, 2015).

  4. 4.

    IPCC Special Report on Global Warming of 1.5°C (eds Masson-Delmotte, V. et al.) (WMO, 2018).

  5. 5.

    Rogelj, J. et al. Scenarios towards limiting global mean temperature increase below 1.5 °C. Nat. Clim. Change 8, 325–332 (2018).

    Article  Google Scholar 

  6. 6.

    Goglio, P. et al. Advances and challenges of life cycle assessment (LCA) of greenhouse gas removal technologies to fight climate changes. J. Clean. Prod. 244, 118896 (2020).

    Article  Google Scholar 

  7. 7.

    Brethomé, F. M., Williams, N. J., Seipp, C. A., Kidder, M. K. & Custelcean, R. Direct air capture of CO2 via aqueous-phase absorption and crystalline-phase release using concentrated solar power. Nat. Energy 3, 553–559 (2018).

    Article  Google Scholar 

  8. 8.

    Socolow, R. et al. Direct Air Capture of CO2 with Chemicals. A Technology Assessment for the APS Panel on Public Affairs (American Physical Society, 2011).

  9. 9.

    Gunnarsson, I. et al. The rapid and cost-effective capture and subsurface mineral storage of carbon and sulfur at the CarbFix2 site. Int. J. Greenh. Gas. Con. 79, 117–126 (2018).

    Article  Google Scholar 

  10. 10.

    Matter, J. M. et al. Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions. Science 352, 1312–1314 (2016).

    Article  Google Scholar 

  11. 11.

    Deutz, S. et al. Cleaner production of cleaner fuels: wind-to-wheel – environmental assessment of CO2-based oxymethylene ether as a drop-in fuel. Energy Environ. Sci. 11, 331–343 (2018).

    Article  Google Scholar 

  12. 12.

    Liu, C. M., Sandhu, N. K., McCoy, S. T. & Bergerson, J. A. A life cycle assessment of greenhouse gas emissions from direct air capture and Fischer–Tropsch fuel production. Sustain. Energy Fuels 4, 3129–3142 (2020).

    Article  Google Scholar 

  13. 13.

    Artz, J. et al. Sustainable conversion of carbon dioxide: an integrated review of catalysis and life cycle assessment. Chem. Rev. 118, 434–504 (2018).

    Article  Google Scholar 

  14. 14.

    Kätelhön, A., Meys, R., Deutz, S., Suh, S. & Bardow, A. Climate change mitigation potential of carbon capture and utilization in the chemical industry. Proc. Natl Acad. Sci. USA 116, 11187–11194 (2019).

    Article  Google Scholar 

  15. 15.

    Ostovari, H., Sternberg, A. & Bardow, A. Rock ‘n’ use of CO2: carbon footprint of carbon capture and utilization by mineralization. Sustain. Energy Fuels 4, 4482–4496 (2020).

    Article  Google Scholar 

  16. 16.

    Nduagu, E., Bergerson, J. & Zevenhoven, R. Life cycle assessment of CO2 sequestration in magnesium silicate rock – a comparative study. Energy Convers. Manag. 55, 116–126 (2012).

    Article  Google Scholar 

  17. 17.

    Smit, B., Reimer, J. A., Oldenburg, C. M. & Bourg, I. C. Introduction to Carbon Capture and Sequestration (Imperial College Press, 2014).

  18. 18.

    Sanz-Pérez, E. S., Murdock, C. R., Didas, S. A. & Jones, C. W. Direct capture of CO2 from ambient air. Chem. Rev. 116, 11840–11876 (2016).

    Article  Google Scholar 

  19. 19.

    McQueen, N. et al. Cost analysis of direct air capture and sequestration coupled to low-carbon thermal energy in the United States. Environ. Sci. Technol. 54, 7542–7551 (2020).

    Article  Google Scholar 

  20. 20.

    Nikulshina, V., Gálvez, M. E. & Steinfeld, A. Kinetic analysis of the carbonation reactions for the capture of CO2 from air via the Ca(OH)2–CaCO3–CaO solar thermochemical cycle. Chem. Eng. J. 129, 75–83 (2007).

    Article  Google Scholar 

  21. 21.

    Nikulshina, V., Gebald, C. & Steinfeld, A. CO2 capture from atmospheric air via consecutive CaO-carbonation and CaCO3-calcination cycles in a fluidized-bed solar reactor. Chem. Eng. J. 146, 244–248 (2009).

    Article  Google Scholar 

  22. 22.

    Azarabadi, H. & Lackner, K. S. A sorbent-focused techno-economic analysis of direct air capture. Appl. Energy 250, 959–975 (2019).

    Article  Google Scholar 

  23. 23.

    Chaikittisilp, W., Kim, H.-J. & Jones, C. W. Mesoporous alumina-supported amines as potential steam-stable adsorbents for capturing CO2 from simulated flue gas and ambient air. Energ. Fuel 25, 5528–5537 (2011).

    Article  Google Scholar 

  24. 24.

    Gebald, C., Wurzbacher, J. A., Borgschulte, A., Zimmermann, T. & Steinfeld, A. Single-component and binary CO2 and H2O adsorption of amine-functionalized cellulose. Environ. Sci. Technol. 48, 2497–2504 (2014).

    Article  Google Scholar 

  25. 25.

    Gebald, C., Wurzbacher, J. A., Tingaut, P. & Steinfeld, A. Stability of amine-functionalized cellulose during temperature-vacuum-swing cycling for CO2 capture from air. Environ. Sci. Technol. 47, 10063–10070 (2013).

    Article  Google Scholar 

  26. 26.

    Gebald, C., Wurzbacher, J. A., Tingaut, P., Zimmermann, T. & Steinfeld, A. Amine-based nanofibrillated cellulose as adsorbent for CO2 capture from air. Environ. Sci. Technol. 45, 9101–9108 (2011).

    Article  Google Scholar 

  27. 27.

    McDonald, T. M. et al. Cooperative insertion of CO2 in diamine-appended metal-organic frameworks. Nature 519, 303–308 (2015).

    Article  Google Scholar 

  28. 28.

    Keith, D. W., Holmes, G., St. Angelo, D. & Heidel, K. A process for capturing CO2 from the atmosphere. Joule 2, 1573–1594 (2018).

    Article  Google Scholar 

  29. 29.

    de Jonge, M. M. J., Daemen, J., Loriaux, J. M., Steinmann, Z. J. N. & Huijbregts, M. A. J. Life cycle carbon efficiency of direct air capture systems with strong hydroxide sorbents. Int. J. Greenh. Gas. Con. 80, 25–31 (2019).

    Article  Google Scholar 

  30. 30.

    Goeppert, A., Czaun, M., Surya Prakash, G. K. & Olah, G. A. Air as the renewable carbon source of the future: an overview of CO2 capture from the atmosphere. Energy Environ. Sci. 5, 7833–7853 (2012).

    Article  Google Scholar 

  31. 31.

    Wurzbacher, J. A., Gebald, C. & Steinfeld, A. Separation of CO2 from air by temperature-vacuum swing adsorption using diamine-functionalized silica gel. Energy Environ. Sci. 4, 3584–3592 (2011).

    Article  Google Scholar 

  32. 32.

    Fasihi, M., Efimova, O. & Breyer, C. Techno-economic assessment of CO2 direct air capture plants. J. Clean. Prod. 224, 957–980 (2019).

    Article  Google Scholar 

  33. 33.

    Wurzbacher, J. A., Gebald, C., Brunner, S. & Steinfeld, A. Heat and mass transfer of temperature–vacuum swing desorption for CO2 capture from air. Chem. Eng. J. 283, 1329–1338 (2016).

    Article  Google Scholar 

  34. 34.

    Wurzbacher, J. A., Gebald, C., Piatkowski, N. & Steinfeld, A. Concurrent separation of CO2 and H2O from air by a temperature-vacuum swing adsorption/desorption cycle. Environ. Sci. Technol. 46, 9191–9198 (2012).

    Article  Google Scholar 

  35. 35.

    Stuckert, N. R. & Yang, R. T. CO2 capture from the atmosphere and simultaneous concentration using zeolites and amine-grafted SBA-15. Environ. Sci. Technol. 45, 10257–10264 (2011).

    Article  Google Scholar 

  36. 36.

    van der Giesen, C. et al. A life cycle assessment case study of coal-fired electricity generation with humidity swing direct air capture of CO2 versus MEA-based postcombustion capture. Environ. Sci. Technol. 51, 1024–1034 (2017).

    Article  Google Scholar 

  37. 37.

    Zhang, X., Bauer, C., Mutel, C. L. & Volkart, K. Life cycle assessment of power-to-gas: approaches, system variations and their environmental implications. Appl. Energy 190, 326–338 (2017).

    Article  Google Scholar 

  38. 38.

    Fuhrman, J. et al. Food–energy–water implications of negative emissions technologies in a +1.5 °C future. Nat. Clim. Change 10, 920–927 (2020).

    Article  Google Scholar 

  39. 39.

    Chatterjee, S. & Huang, K.-W. Unrealistic energy and materials requirement for direct air capture in deep mitigation pathways. Nat. Commun. 11, 3287 (2020).

    Article  Google Scholar 

  40. 40.

    Realmonte, G. et al. Reply to “High energy and materials requirement for direct air capture calls for further analysis and R&D”. Nat. Commun. 11, 3286 (2020).

    Article  Google Scholar 

  41. 41.

    Realmonte, G. et al. An inter-model assessment of the role of direct air capture in deep mitigation pathways. Nat. Commun. 10, 3277 (2019).

    Article  Google Scholar 

  42. 42.

    ISO 14040:2006. Environmental Management — Life Cycle Assessment — Principles and Framework (International Organization for Standardization, 2006).

  43. 43.

    ISO 14044:2006. Environmental Management — Life Cycle Assessment — Requirements and Guidelines (International Organization for Standardization, 2006).

  44. 44.

    Climeworks Raises CHF 30.5M (USD 30.8M) to Commercialize Carbon Dioxide Removal Technology Press release (Climeworks, 2018).

  45. 45.

    Sternberg, A. & Bardow, A. Power-to-What? – Environmental assessment of energy storage systems. Energy Environ. Sci. 8, 389–400 (2015).

    Article  Google Scholar 

  46. 46.

    Global Land Outlook 1st edn (United Nations Convention to Combat Desertification, 2017).

  47. 47.

    Negative Emissions Technologies and Reliable Sequestration: a Research Agenda (National Academies of Sciences, Engineering, and Medicine, 2019).

  48. 48.

    The International Reference Life Cycle Data System (ILCD) Handbook - General Guide for Life Cycle Assessment - Detailed Guidance (Publications Office of the European Union, 2010).

  49. 49.

    Tanzer, S. E. & Ramírez, A. When are negative emissions negative emissions? Energy Environ. Sci. 12, 1210–1218 (2019).

    Article  Google Scholar 

  50. 50.

    Müller, L. J. et al. A guideline for life cycle assessment of carbon capture and utilization. Front. Energy Res. (2020).

  51. 51.

    Lee, S.-Y. & Park, S.-J. A review on solid adsorbents for carbon dioxide capture. J. Ind. Eng. Chem. 23, 1–11 (2015).

    Article  Google Scholar 

  52. 52.

    Sala, S., Crenna, E., Secchi, M. & Pant, R. Global Normalisation Factors for the Environmental Footprint and Life Cycle Assessment (Publications Office of the European Union, 2017).

  53. 53.

    GaBi Software-System and Database for Life Cycle Engineering, DB 8.7 - SP 39 (thinkstep AG, 2019).

  54. 54.

    ecoinvent data version 3.5, cut-off (Swiss Centre for Life Cycle Inventories, 2019).

  55. 55.

    Product Environmental Footprint Category Rules Guidance version 6.3 – May 2018 (European Commission, 2018).

  56. 56.

    International Reference Life Cycle Data System (ILCD) Handbook - Recommendations for Life Cycle Impact Assessment in the European Context from the European Commission. (Publications Office of the European Union, 2011).

  57. 57.

    Supporting Information to the Characterisation Factors of Recommended EF Life Cycle Impact Assessment Methods: New Methods and Differences with ILCD (Publications Office of the European Union, 2018).

  58. 58.

    Wegener Sleeswijk, A., van Oers, L. F. C. M., Guinée, J. B., Struijs, J. & Huijbregts, M. A. J. Normalisation in product life cycle assessment: an LCA of the global and European economic systems in the year 2000. Sci. Total Environ. 390, 227–240 (2008).

    Article  Google Scholar 

  59. 59.

    Crenna, E., Secchi, M., Benini, L. & Sala, S. Global environmental impacts: data sources and methodological choices for calculating normalization factors for LCA. Int. J. LCA 24, 1851–1877 (2019).

    Article  Google Scholar 

  60. 60.

    Pizzol, M. et al. Normalisation and weighting in life cycle assessment: quo vadis? Int. J. LCA 22, 853–866 (2017).

    Article  Google Scholar 

  61. 61.

    Energy Technology Perspectives 2017: Catalysing Energy Technology Transformations (International Energy Agency, 2017).

  62. 62.

    Esen, H., Inalli, M., Esen, M. & Pihtili, K. Energy and exergy analysis of a ground-coupled heat pump system with two horizontal ground heat exchangers. Build. Environ. 42, 3606–3615 (2007).

    Article  Google Scholar 

  63. 63.

    Ozgener, O. & Hepbasli, A. Experimental performance analysis of a solar assisted ground-source heat pump greenhouse heating system. Energ. Build. 37, 101–110 (2005).

    Article  Google Scholar 

  64. 64.

    Averfalk, H., Ingvarsson, P., Persson, U., Gong, M. & Werner, S. Large heat pumps in Swedish district heating systems. Renew. Sust. Energ. Rev. 79, 1275–1284 (2017).

    Article  Google Scholar 

  65. 65.

    David, A., Mathiesen, B. V., Averfalk, H., Werner, S. & Lund, H. Heat roadmap Europe: large-scale electric heat pumps in district heating systems. Energies 10, 578 (2017).

    Article  Google Scholar 

  66. 66.

    Karlsdóttir, M. R., Palsson, O. P. & Palsson, H. LCA of combined heat and power production at Hellisheiði geothermal power plant with focus on primary energy efficiency. In Proc. 12th International Symposium on District Heating and Cooling (Tallinna Tehnikaülikool, Nordic Energy Research and norden, 2010).

  67. 67.

    Karlsdóttir, M. R., Pálsson, Ó. P., Pálsson, H. & Maya-Drysdale, L. Life cycle inventory of a flash geothermal combined heat and power plant located in Iceland. Int. J. LCA 20, 503–519 (2015).

    Article  Google Scholar 

  68. 68.

    Ekvall, T. & Weidema, B. P. System boundaries and input data in consequential life cycle inventory analysis. Int. J. LCA 9, 161–171 (2004).

    Article  Google Scholar 

  69. 69.

    Sternberg, A. & Bardow, A. Life cycle assessment of power-to-gas: syngas vs methane. ACS Sustain. Chem. Eng. 4, 4156–4165 (2016).

    Article  Google Scholar 

  70. 70.

    Götz, M. et al. Renewable power-to-gas: a technological and economic review. Renew. Energy 85, 1371–1390 (2016).

    Article  Google Scholar 

  71. 71.

    Sternberg, A., Jens, C. M. & Bardow, A. Life cycle assessment of CO2-based C1-chemicals. Green Chem. 19, 2244–2259 (2017).

    Article  Google Scholar 

  72. 72.

    Bongartz, D. et al. Comparison of light-duty transportation fuels produced from renewable hydrogen and green carbon dioxide. Appl. Energy 231, 757–767 (2018).

    Article  Google Scholar 

  73. 73.

    Cuéllar-Franca, R. M. & Azapagic, A. Carbon capture, storage and utilisation technologies: a critical analysis and comparison of their life cycle environmental impacts. J. CO2 Util. 9, 82–102 (2015).

    Article  Google Scholar 

  74. 74.

    Boot-Handford, M. E. et al. Carbon capture and storage update. Energy Environ. Sci. 7, 130–189 (2014).

    Article  Google Scholar 

  75. 75.

    Koornneef, J., van Keulen, T., Faaij, A. & Turkenburg, W. Life cycle assessment of a pulverized coal power plant with post-combustion capture, transport and storage of CO2. Int. J. Greenh. Gas. Con. 2, 448–467 (2008).

    Article  Google Scholar 

  76. 76.

    Pehnt, M. & Henkel, J. Life cycle assessment of carbon dioxide capture and storage from lignite power plants. Int. J. Greenh. Gas. Con. 3, 49–66 (2009).

    Article  Google Scholar 

  77. 77.

    Clark, D. E. et al. CarbFix2: CO2 and H2S mineralization during 3.5 years of continuous injection into basaltic rocks at more than 250 °C. Geochim. Cosmochim. Acta 279, 45–66 (2020).

    Article  Google Scholar 

  78. 78.

    Global Energy & CO2 Status Report 2017 (International Energy Agency, 2018).

Download references


We gratefully acknowledge funding by the German Federal Ministry of Education and Research (BMBF) within the Kopernikus Project P2X: flexible use of renewable resources—exploration, validation and implementation of ‘Power-to-X’ concepts. In particular, we thank the Power-to-X project partner Climeworks who provided data, insight and expertise in their technology that greatly assisted our research as part of the publicly funded Kopernikus project Power-to-X. We thank L. Kroeger and K. Leonhard for the valuable discussions on reaction kinetics and thermochemistry, and D. Bongartz for conducting the process simulations on heat integration of DAC and synthetic fuel production. We further thank N. McQueen and J. Wilcox for comments helping us to improve our study, and V. Beckert, L. Dörpinghaus, N. Groll, F. Pellengahr and N. Tigu for their technical support.

Author information




S.D. and A.B. designed and performed research, analysed data and wrote the paper.

Corresponding author

Correspondence to André Bardow.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Energy thanks Derrick Carlson and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Notes 1–12, Figs. 1–51 and Tables 1–30.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Deutz, S., Bardow, A. Life-cycle assessment of an industrial direct air capture process based on temperature–vacuum swing adsorption. Nat Energy 6, 203–213 (2021).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing